Quenched dynamics of classical isolated systems: The spherical spin model with two-body random interactions or the Neumann integrable model

We study the Hamiltonian dynamics of the spherical spin model with fully-connected two-body random interactions. In the statistical physics framework, the potential energy is of the so-called p = 2 kind, closely linked to the scalar field theory. Most importantly for our setting, the energy conservi...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Cugliandolo, L.F., Lozano, G.S., Nessi, N., Picco, M., Tartaglia, A.
Formato: JOUR
Materias:
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_17425468_v2018_n6_p_Cugliandolo
Aporte de:
id todo:paper_17425468_v2018_n6_p_Cugliandolo
record_format dspace
spelling todo:paper_17425468_v2018_n6_p_Cugliandolo2023-10-03T16:30:24Z Quenched dynamics of classical isolated systems: The spherical spin model with two-body random interactions or the Neumann integrable model Cugliandolo, L.F. Lozano, G.S. Nessi, N. Picco, M. Tartaglia, A. dynamical processes energy landscapes ergodicity breaking numerical simulations We study the Hamiltonian dynamics of the spherical spin model with fully-connected two-body random interactions. In the statistical physics framework, the potential energy is of the so-called p = 2 kind, closely linked to the scalar field theory. Most importantly for our setting, the energy conserving dynamics are equivalent to the ones of the Neumann integrable model. We take initial conditions from the Boltzmann equilibrium measure at a temperature that can be above or below the static phase transition, typical of a disordered (paramagnetic) or of an ordered (disguised ferromagnetic) equilibrium phase. We subsequently evolve the configurations with Newton dynamics dictated by a different Hamiltonian, obtained from an instantaneous global rescaling of the elements in the interaction random matrix. In the limit of infinitely many degrees of freedom, , we identify three dynamical phases depending on the parameters that characterise the initial state and the final Hamiltonian. We next set the analysis of the system with finite number of degrees of freedom in terms of N non-linearly coupled modes. We argue that in the limit the modes decouple at long times. We evaluate the mode temperatures and we relate them to the frequency-dependent effective temperature measured with the fluctuation-dissipation relation in the frequency domain, similarly to what was recently proposed for quantum integrable cases. Finally, we analyse the N - 1 integrals of motion, notably, their scaling with N, and we use them to show that the system is out of equilibrium in all phases, even for parameters that show an apparent Gibbs-Boltzmann behaviour of the global observables. We elaborate on the role played by these constants of motion after the quench and we briefly discuss the possible description of the asymptotic dynamics in terms of a generalised Gibbs ensemble. © 2018 IOP Publishing Ltd and SISSA Medialab srl. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_17425468_v2018_n6_p_Cugliandolo
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic dynamical processes
energy landscapes
ergodicity breaking
numerical simulations
spellingShingle dynamical processes
energy landscapes
ergodicity breaking
numerical simulations
Cugliandolo, L.F.
Lozano, G.S.
Nessi, N.
Picco, M.
Tartaglia, A.
Quenched dynamics of classical isolated systems: The spherical spin model with two-body random interactions or the Neumann integrable model
topic_facet dynamical processes
energy landscapes
ergodicity breaking
numerical simulations
description We study the Hamiltonian dynamics of the spherical spin model with fully-connected two-body random interactions. In the statistical physics framework, the potential energy is of the so-called p = 2 kind, closely linked to the scalar field theory. Most importantly for our setting, the energy conserving dynamics are equivalent to the ones of the Neumann integrable model. We take initial conditions from the Boltzmann equilibrium measure at a temperature that can be above or below the static phase transition, typical of a disordered (paramagnetic) or of an ordered (disguised ferromagnetic) equilibrium phase. We subsequently evolve the configurations with Newton dynamics dictated by a different Hamiltonian, obtained from an instantaneous global rescaling of the elements in the interaction random matrix. In the limit of infinitely many degrees of freedom, , we identify three dynamical phases depending on the parameters that characterise the initial state and the final Hamiltonian. We next set the analysis of the system with finite number of degrees of freedom in terms of N non-linearly coupled modes. We argue that in the limit the modes decouple at long times. We evaluate the mode temperatures and we relate them to the frequency-dependent effective temperature measured with the fluctuation-dissipation relation in the frequency domain, similarly to what was recently proposed for quantum integrable cases. Finally, we analyse the N - 1 integrals of motion, notably, their scaling with N, and we use them to show that the system is out of equilibrium in all phases, even for parameters that show an apparent Gibbs-Boltzmann behaviour of the global observables. We elaborate on the role played by these constants of motion after the quench and we briefly discuss the possible description of the asymptotic dynamics in terms of a generalised Gibbs ensemble. © 2018 IOP Publishing Ltd and SISSA Medialab srl.
format JOUR
author Cugliandolo, L.F.
Lozano, G.S.
Nessi, N.
Picco, M.
Tartaglia, A.
author_facet Cugliandolo, L.F.
Lozano, G.S.
Nessi, N.
Picco, M.
Tartaglia, A.
author_sort Cugliandolo, L.F.
title Quenched dynamics of classical isolated systems: The spherical spin model with two-body random interactions or the Neumann integrable model
title_short Quenched dynamics of classical isolated systems: The spherical spin model with two-body random interactions or the Neumann integrable model
title_full Quenched dynamics of classical isolated systems: The spherical spin model with two-body random interactions or the Neumann integrable model
title_fullStr Quenched dynamics of classical isolated systems: The spherical spin model with two-body random interactions or the Neumann integrable model
title_full_unstemmed Quenched dynamics of classical isolated systems: The spherical spin model with two-body random interactions or the Neumann integrable model
title_sort quenched dynamics of classical isolated systems: the spherical spin model with two-body random interactions or the neumann integrable model
url http://hdl.handle.net/20.500.12110/paper_17425468_v2018_n6_p_Cugliandolo
work_keys_str_mv AT cugliandololf quencheddynamicsofclassicalisolatedsystemsthesphericalspinmodelwithtwobodyrandominteractionsortheneumannintegrablemodel
AT lozanogs quencheddynamicsofclassicalisolatedsystemsthesphericalspinmodelwithtwobodyrandominteractionsortheneumannintegrablemodel
AT nessin quencheddynamicsofclassicalisolatedsystemsthesphericalspinmodelwithtwobodyrandominteractionsortheneumannintegrablemodel
AT piccom quencheddynamicsofclassicalisolatedsystemsthesphericalspinmodelwithtwobodyrandominteractionsortheneumannintegrablemodel
AT tartagliaa quencheddynamicsofclassicalisolatedsystemsthesphericalspinmodelwithtwobodyrandominteractionsortheneumannintegrablemodel
_version_ 1807321625731792896